1. The Field of the Invention
The present invention relates to orthotics and custom conformable devices, including custom fitting orthotics.
2. The Relevant Technology
Orthotics is the science of treating anatomical disorders, such as joint, bone, or muscle disorders, with anatomical supports, such as braces, inserts, and cushions. Anatomical supports have been commonly used both to increase comfort and to aid in medical treatments. For instance, arch supports have been used for many years for both added foot comfort when wearing shoes, and for treatment of foot and knee problems. Arch supports fall into one of two common categories: (1) inserts that increase padding or cushion; and (2) corrective devices, commonly referred to as orthotics, that correct foot position to relieve stress on the foot, knee or leg. Orthotics are commonly used to support feet with normal alignment; and to correct feet that have excessive pronation.
Pronation is the inward rotation of the middle part of the foot, and is commonly associated with a low arch. One function of orthotics is to prevent the natural pronation of the normal foot during walking. Three separate arches are described that support the weight of the body. These arches are not rigid and provide flexibility and leverage for walking. With normal walking, the foot lands in a supinated or high arch position at heel strike. As weight is accepted by the foot during walking, the arch flattens and the foot pronates until it is at maximum pronation and maximum load, approximately 25% of the way into the stance. The foot then resupinates until push off, when all weight is removed from the foot. One function of orthotics is to shorten the period of time in pronation during stance phase of gait to reduce stress on the tendons of the foot and knee. Orthotics should exert a gentle, consistent pressure to bring the foot into proper alignment. Correction of hyper pronation, or “flat feet,” is another function of orthotics. The relief of excessive pronation can relieve other conditions such as shin splints or kneecap problems.
Two categories of orthotics are commonly available: (1) ready-made orthotics; and (2) custom molded or custom fit orthotics. Ready-made orthotics typically come in standard sizes and are relatively inexpensive. One problem with ready-made orthotics is that they often fit poorly or are uncomfortable because they do not accommodate the unique shape and size of each patient's foot. Custom molded orthotics are intended to solve this problem. Custom fit orthotics are custom made to fit a particular foot size and shape, and thus they ought to fit comfortably on each patient. One problem with custom molded orthotics is that they often require the services of an expert to custom fit the orthotic, and they can be cost prohibitive due to the time and expertise required to custom make each orthotic.
Attempts have been made to provide custom molded orthotics that are custom fit by the user and less cost prohibitive than traditional custom molded orthotics. One such attempt utilizes a variety of chemicals in a liquid state placed inside an insole. First, the user initiates a chemical reaction in the chemicals within the insole. Next, the user places the insole inside a shoe, and wears the shoe as normally worn. The weight of the user on the insole molds the liquid chemicals inside insole to conform to the shape of the user's foot. The chemical reaction occurring inside the insole causes the chemicals to transform from a liquid state to a solid state, resulting in a solid orthotic in the shape of the user's foot. Although such a custom molded orthotic is less cost prohibitive and does not require an expert to mold the orthotic, the problem with such molded orthotics is that the user cannot adjust the level of support of the orthotic. The amount of chemicals in the insole determines the size and level of support of the orthotic, thus the orthotic will not give the desired level of support unless it initially contains the correct amount of liquid chemicals. The desired level of support may not be known by the user until the chemicals in the orthotic have set and the user feels the level of support given by the orthotic. However, once the chemicals have set, the level of support cannot be adjusted. Thus, the orthotic will conform to the user's foot but often does not provide the level of support desired.
Another attempt to provide custom fit orthotics that are custom fit by the user and less cost prohibitive than traditional custom molded orthotics utilizes a bladder filled with air. An air bladder is placed inside an insole, which is placed inside the user's shoe. Some embodiments require the user to use a pump to inflate the bladder before the shoe is placed on the user's foot. Other embodiments incorporate a pump inside the insole or shoe. The weight of the user works the pump, which inflates the bladder as the user walks while wearing the shoe. The inflated bladder is intended to conform to the shape of the user's foot as weight is placed on the user's foot.
Although some of such conventional custom fit orthotics allow the user to adjust the level of support of the orthotic, these custom fit orthotics may be complex to manufacture, involving complex pumps to inflate the bladder. The complex design and numerous parts required to inflate the bladder can be cost prohibitive. Further, the inflated bladder does not retain the shape of the user's foot when weight is removed from the foot.
The bladder is filled in these conventional devices with a fluid, in this case a gas, that freely shifts and flows inside the bladder as the weight on the user's foot shifts, thus causing the inflated bladder to change shape. Such a shifting of shape during different stages of walking may result in undesired changing levels of support.
What is needed is a custom fit support that conforms to shape of the user's anatomy, retains the shape of the user's anatomy, is efficient to manufacture, is relatively inexpensive, and has an adjustable level of support.